/* var a = prompt("价格"),
	b = prompt("数量"),
	c = Number(a) * Number(b),
	d = 1200;
document.write('商品总价：' + c + '<br/>');
if (c >= 1000) {
	document.write('打折后价格：' + 0.9 * c);
} 
if (d >= c) {
	alert("pay success");
} else {
	alert("pay error");
}
 */
var a=80,b=parseInt(a/10);
switch (b){
	case 9:case 10:
	console.log('优秀');
	break;
	case  8:
	console.log('良好');
	break;
	case 7:
	console.log('中等')
	break;
	case 6:
	console.log('及格')
	break;
	default:
	console.log('不及格')
	break;
}